This invention relates to an improved rail seating and fastening device. More particularly, this invention relates to an improved adjustable, relatively (substantially) maintenance-free rail fastening device that provides for firm engagement of both end portions of the device.
Rails used in the construction and operation of modern railway systems are constantly subjected to strong forces and loadings during their useful lives. Since several tons of machinery, as well as millions of dollars of goods and equipment and countless human lives pass over these rails every day, it is understandably of prime importance that the rails remained at all times in a stable, substantially stationary and structurally rigid condition.
Although the rails themselves are generally of a substantially stable construction, they are laid down in continuous or semi-continuous sections. In use, these rails are subjected to a number of external forces not the least of which is a train or similar vehicle rolling over the track. These external forces have the tendency of introducing a great degree of travel into an unrestrained rail, potentially resulting in derailment and disaster. For that reason, attempts have been continuously made to provide devices that positionally stabilize the rails by fastening them to rail supports or tie plates.
The prior art devices have been of two general types, the first type of device being a mechanical holder construction that attempts to catch the edge of one flange of the rail under the holder and then bolt the holder to the rail support or tie plate. Other devices have utilized a spring clip construction that has contacted only the inner surface of one flange of the rail, at a distance somewhat inward from the edge of the flange. These devices depend upon the torsional or bending moment force of the arm of the clip to exert a force on the horizontal plane of the fastening device, as well as on the rail, to positionally stabilize both. These devices have likewise depended upon threaded fasteners to engage and secure them to rail supports and tie plates.
The problem inherent with such structures is that forces encountered can be of such a magnitude as to loosen, strip or sheer such threaded fasteners, resulting in a system failure. Modern rail technology has made the ability to accommodate different gauge rail stock a necessity. Existing rail fastening devices have usually been either unadjustable or have necessitated a loosening and tightening of a threaded element to accomplish this result. Even those devices that have been capable of adjustment have suffered a resultant weakening of the threaded elements, through successive loosenings and tightenings.